Open AccessMarked variability in bioactivity between commercially available bovine colostrum for human use; implications for clinical trials
Author(s) -
Raymond J. Playford,
M.B. Cattell,
Tania Marchbank
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0234719
Subject(s) - colostrum , in vitro , in vivo , growth factor , antibody , biological activity , biology , pharmacology , chemistry , andrology , medicine , immunology , biochemistry , receptor , microbiology and biotechnology
Background Colostrum, the milk produced during first few days after birth, is rich in immunoglobulins, antimicrobial peptides & growth factors. Multiple clinical trials using bovine colostrum are ongoing but with no assessment of test product bioactivity. Objectives To examine variability of bioactivity between 20 commercial colostrum products, contribution of TGFβ and EGFR in mediating effects, heat sensitivity of bioactivity and changes in bioactivity of colostrum milkings in the days following calving. Design In vitro bioactivity used AGS, RIE-1 and Caco-2 cell proliferation (Alamar blue) and migration (wounded monolayers) assays. Changes in colostrum bioactivity determined following addition of TGFβ-neutralising antibody, EGFR blocker (Typhostin) and after heating (40–60°C, 60 min). In vivo bioassay assessed ability of colostrum gavage (2ml, 7mg/ml) to reduce gastric damage (NSAID + restraint) in rats. Milkings from 6 cows, days 0–3 post calving were assessed for bioactivity and growth factor concentrations. Result Six-fold differences in pro-proliferative and migratory activity were seen comparing commercial products. Comparison of most- and least-active samples from in vitro studies showed two- to three-fold differences in ability to reduce gastric injury (86% reduction using most-active vs 48% using least-active, p<0.01). Tyrphostin reduced pro-migratory and proliferative activity by 23% and 55%. TGFβ neutralisation reduced migratory activity by 83% but did not affect proliferation Heating colostrum powder to 50°C did not affect immunoactivity of haptoglobin, EGF, TGFβ, IgG, IGF-1 or betacellulin but decreased bioactivity by >40%. Milking studies showed high bioactivity during first and second milkings on day 0 but 77% reduction by day 3. Changes in total protein, haptoglobin, EGF, TGFβ, IgG and IGF-1 paralleled falls in bioactivity. Conclusion Commercial colostrum products possess widely different bioactivity. Variation in heat exposure and/or proportion of day 0 colostrum content may contribute to this. Assessment of colostrum bioactivity has advantages to growth factor quantitation for quality control.